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Sept. 6, 1932. w BQWER ELECTROMECHANICAL VIBRAT OR MOUNTING Filed Jan. 50. 1929 .INVENTOR. W 6 693W,

BY t; A TORNEY Patented septr fi 1 932 2 wean 1a sown, or .wasnmoromnrsmie'r or-1001mm a I mac'raomacwrcan mama maxim Appllcationflled was so, LSexlal m. aaaz za. i v

to reduced to a minimum.

Another object of this invention is to provide a mounting for an electromechanical v1- electromechanical vibrator and the electrodes is employed for connecting it into circuit is substantially constant. I

Still another object of this invention is to provide a mounting for a mechanically vibratile element in which the element is supported 20 at its nodal point.

A further object of this invention is to iezo electric element in which substantial y no restraining provide a mountingfor a following specification and the annexed claims.

According to thls invention a plezo electric element or other electromechanical vibrator [of the first mode-"ofvi'bratien of the piezo is provided with a mounting in which the frictional resistance to the elements motion between the electrodes is reduced to a minimum by providing coatings, which serve as electrodes, of extremely light material. Greater precision in the operation of the elements is also obtained by suspending the element in its holder at a nodal point.

- In the drawing, Figure 1 is a perspective view of a preferred embodiment of this invention and Fig. 2 is a cross-sectional view inelevation along the line 2-2 of Fig. 1.

" ments,such as -silicate o'f or "potssmaintained taut with substantially no inter-.

erence numeral 1 indicates a base :of insulatingmateria'l. This base may be madeofany insulating material suchzas phenol :condensation products, dried wood impregnated with I sheliaesywaxes orrosins; hard rubberion vitll reous materials suchnas'quartzand glass.

U-shaped supporting member 2 is positioned upon the b'ase lg, This member maybe made a of either 1 insulating 'material, 'sueh as" iused quartz, glass, hard -;rubber or similarf sub-' stances or may be made' ofmetals such :as

aluminum; copper or bronze, suitable for brator'in which the area of contact of the electrical apparatus. A- cross mmeber 3. is attached to the extremities of the u shaped v member 2. The piezo 'electric elementA is supported by flexible cords 5, v6 and 7' which are attached" to the members2 and="3. These cords are preferably of silk although other materials "such as j wax impvegnated cotton may be us'ed. 5 The-Inember 3 maybe dispensed with and the cords [5,-6' and"75attached v directly to the basemember 1. 'lhe eord fiis attached to ascr'ew 13 which is'provided in the member 2 for maintaining thisoord undera certain degree of tension. "Th e 51 and"? arenot subjected to as great atension asis applied to the cord 6 since-these cords are employed to prevent the piezoelectricelementfrom turning. various'methods of at; tachingthecords to the'piezo electric element ymayibe'yemployed- For example the cords I may be T ielenaent or they my be held upon the element by means of oesiurm E s The cord fi -ispositioned t. he nodal o electric element.- This cord maytherefore'be ference to the free oscillation ofthe element The cords t5 and 7 are usually'not maintained under tension and consequently introduce no oscillation restraining forces of appreciable magnitude upon. the element; The piejzo gleetrio element 14.. is provided with: coatings s and 14 to which conductor's and 10 are nected The conductorsa andfllQ areeither soldered for cemented to the; coatings: ,8 and 5 Referring to the drawing in detail, the refe a ela f e serve as terminals for the conductors 9 and 10, respectively, whereby the element 4 is connected into circuit. Coatings 8 and 14 may consist of gold leaf cemented to the surface of the piezo electric element with cements such as shellac, sodium or potassium silicate or similar materials. Metals such as platinum may be sputtered against the surface of the piezo electric crystal and serve as very serviceable and permanent coatings, especially where piezo electric crystal elements of extreme accuracy and precision are required.

While I have described my invention in one of its preferred embodiments, I desire it to be understood that modifications may bemade and that I intend no limitations upon the invention other than those imposed by the scope of the annexed claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows I said crystal, a frame member, a taut flexible member attached to said frame member and to said crystal substantially at its fundamen tal nodal point, and other flexible members attached to said frame member and embracing said crystal and its electrodes on opposite sides of its nodal point and maintained under substantially no tension.

3. In a piezo electric crystal unit, a piezo electric crystal, electrodes in contact with said crystal, a frame member, a taut flexible member attached to said frame member and to said crystal substantially at its fundamental nodal point, other flexible members attached to said frame member and embracing said crystal and its electrodes on opposite sides of its nodal point and maintained under substantially less tension than said taut flexible member, and means for adjusting the tension of said taut flexible member.

4. In a piezo electric crystal unit, a piezo electric crystal having metallic films deposited on opposite faces thereof, a frame member, a taut flexible member attached to said frame member and to said crystal substantially at its fundamental nodal point, other flexible members attached to said frame member and embracing said crystal and its electrodes on opposite sides of its nodal point and maintained under substantially less tension than said taut flexible member, said flexible members being mounted for embracing and supporting in contiguous relation said crystal and said metallic films thereon deposited.

5. In a piezo electric crystal unit, a piezo 

